ROTATIONAL ALIGNMENT OF PRODUCT MOLECULES FROM THE REACTION Ca + HCl→CaCl + H

The product rotational polarization in the Ca + HCl→CaCl + H reaction at collision energy of 20 kcal/mol has been studied via the quasiclassical trajectory method on a new ab initio potential surface. The P(θ r ) distribution of angle between k and j′, and the dihedral angular distribution P(Φ r ) characterizing k - k′ - j′ correlation are discussed, the angle distribution P(θ r , Φ r ) of product rotational vectors in the form of polar plot in θ r and Φ r are shown. Furthermore, four PDDCSs (2π/σ)(dσ00/dωt), (2π/σ)(dσ20/dωt), (2π/σ)(dσ22+/dωt) and (2π/σ)(dσ21-/dωt) are also presented. The present calculations reveal that the product rotational alignment is very strong. Finally, the state distributions of the product CaCl are investigated. The results showed that the CaCl product was formed with high vibrational and rotational excitation.

QUASI-CLASSICAL TRAJECTORY CALCULATION OF THE CHEMICAL REACTION Ca + CH3Br

The dynamical property of ground state CaBr formed in the reaction of Ca atom with CH 3 Br has been studied with the quasi-classical trajectory method based on a constructed extended London-Eyring-Polanyi-Sato potential energy surface. In this paper, we report state-to-state distributions in the reaction of Ca with CH 3 Br . They are vibrational distribution, rotational distribution, rotational alignments of the product CaBr , and reaction cross section, which are under detailed investigation. The vibrational distribution of CaBr clearly shows that the peak is located at v = 8 at collision energy E col = 12.22 kcal / mol . The calculated results also show that the peak value of rotational population of the product CaBr is located at J = 50 at collision energy 12.22 kcal/mol. The reaction cross section increases with the increasing collision energy from 0.15 to 0.53 eV. The product rotational alignments deviate slightly from -0.5 and increase while the collision energy of reagent increase. By comparing with the experimental data, it can be found that the theoretical results closely agree with the experimental ones.